Unanswered: When are the heights of components known?

Unanswered: When are the heights of components known?

If I'm building custom widgets (toolbars, button bars, etc...) when is the height for those components known? Specifically, I'm interested in the offset height.

The issue I'm seeing is that if I set the height on the north border of a border layout based on the value of the noarg getOffsetHeight() on the north border component, it's not large enough and the top of the center component is hidden behind the north component.

In general, it seems like things misbehave if absolute sizes aren't used everywhere. But If I want a component to use all available remaining space and that component contains a grid, the grid won't scroll unless I set a fixed height on the grid. In fact, it will render rows off the bottom of the viewport if the rows are tall enough.